Three Phase Transformer Ratio Meter Standard Series

TRT Three Phase Transformer Ratio Meter Standard Series

TRT is based on state-of-the-art technology, using the most advanced technique available today. The test equipment can be used to test both single-phase and three-phase transformers, both with and without tap changer in accordance with the requirements of IEC 60076-1.

For a three-phase measurement, the test set is connected to all three phases of a transformer. If specific vector diagrams are selected for different types of transformers, the TRT will perform a specific test for each type of transformer (i.e. single-phase Delta-to-Star, Star-to-Delta, Delta-to-Delta, Star-to-Star, Delta-to-Zig-Zag, etc.) without the need to change the test connection cables. In addition, you can test with the true three-phase test voltage, allowing you to test any type of transformer. After the test, it shows a ratio of turns, phase change and excitation current, all obtained with three-phase, single-phase and/or true testing.

TRT allows users to enter the voltages from the nameplate for calculation of the turn ratio deviation. This function eliminates any error caused by the operator's manual calculation. The TRT also compares the test result to the nameplate ratio and prints the % error for each test.

Error omens operating condition messages identify incorrect test conditions, abnormal operating problems, or transformer problems. TRT has a very high capacity to cancel electrostatic and electromagnetic interference in HV electric fields. This is achieved through very efficient filtration. Filtration is done using proprietary hardware and software design solutions.

Application

The instrument application list includes:

Transformer ratio measurement

Calculates the deviation of the transformation ratio

Measurement of the excitation current

Phase angle measurement

Automatic vector group detection

Verification of the demagnetization process

Magnetic balance test

Connection of TRT to Test Object

Three-phase transformer

TRT is programmed to automatically test the winding ratio, phase shift and excitation current of power and distribution transformer types defined by IEC/IEC, IEEE and ANSI standards. Using two sets of four cables, all primary and secondary side bushings are connected only once.

Connection of TRT to three-phase transformer

Three-phase autotransformer

TRT is also programmed to automatically test the winding ratio, phase shift and excitation current of autotransformer types defined by IEC/IEC, IEEE and ANSI standards. Using two sets of four cables, all primary and secondary side bushings are connected only once.

Single-phase transformer

Although it is a three-phase device, TRT is capable of testing single-phase transformers. A special cable set or a three-phase cable assembly can be used for this purpose.

Advantages and features

True three-phase test voltage

TRT (except TRT03) is a true three-phase transformer ratio meter. Unlike other so-called "three-phase" testers that allow only three transformer phases to be connected at a time, TRT3x also has the ability to produce a true three-phase test voltage, without the need for additional devices or modules. This allows for testing any type of transformer, including special designs such as phase shifting, arc furnace, rectifier transformers, etc. In addition to measuring a transformer ratio, it can also measure a voltage ratio of three-phase transformers, simulating real working conditions of the transformer. By applying a true three-phase test voltage, and by measuring the induced three-phase voltage, TRT3x is able to determine the actual phase changes between the HV and LV sides and not just the 0 or 180 degree change that is obtained by testing transformers with the single-phase transformer ratio test.

Accuracy

The highest accuracy on the market, for all three measured parameters - ratio, excitation current and phase angle - makes potential transformer irregularities and defects more visible.

Resolution

The measurement of the excitation current is important for determining problems in the magnetic core of the transformer. The high measurement resolution allows better monitoring of the current trend across all tap changer positions.

Interchangeable cables with TWATRT use the same cable set as the TWA Three-Phase Winding Analyzer. This allows a unique cable configuration to perform six tests: turn ratio, excitation current, phase angle, winding resistance, on-load tap changer analysis - DVtest, and demagnetization, thus making TRT and TWA a measurement system.

Vector Group Detection

TRT is able to automatically detect the vector group of three-phase transformers and auto-transformers. This is possible with and without PC software.

A-Win Software

A-Win software is included in the purchase price, and all updates are free. The software allows full control of TRT functions from a PC, such as creating and recording test plans, and downloading test results from the instrument's internal memory. All results are presented numerically and graphically, for easy and convenient analysis. Test results can be exported directly to excel sheet. The customized test report can be generated, edited, saved in various file formats including pdf and print.

The magnetic balance test

This test helps to detect possible problems in the magnetic core of the transformer. The test is fully automatic and does not require changes to the cable configuration by comparing the winding ratio test. The results are presented both numerically and graphically.

The highest accuracy on the market, for all three measured parameters - winding ratio, excitation current and phase angle - makes potential transformer irregularities and defects more visible.

Memory

There is enough memory in the TRT to store 200 test records. Each record consists of 50 test readings.

USB Flash Drive

The results can also be exported to a USB stick via an integrated USB flash drive.

Tap changer control unit

TRT has a built-in tap changer control unit, which allows remote operation of the on-load tap changer. A single operator can perform complete tests very quickly.

Built-in printer

A 112 mm built-in thermal printer is an optional accessory.